The prevalence of physical, psychological, and sexual gender-based violence (GBV) is staggeringly high among young, married women in India. However, few GBV prevention interventions have been implemented, and none of these interventions has been rigorously evaluated. We aim to fill this gap by conducting exploratory research on an innovative women's empowerment-based GBV prevention intervention. The proposed study builds on our previous research in urban poor communities in Bangalore, India, which revealed that efforts to enhance young, married women's power and to mitigate GBV will be limited if the broader context of their lives, which is shaped mainly by the marital family, is unaddressed. Previous research suggests that mothers-in-law (MILs) are a strategic familial entry point and that it may be possible to redirect the power they wield in the family toward reducing GBV against daughters-in-law (DILs). Based on this evidence and women's empowerment approaches that have successfully reduced GBV elsewhere, we developed the intervention Dil Mil (meaning "Hearts Together" in India's national language, Hindi). Guided by the Social Cognitive Theory and Heise's social-ecological framework of GBV, Dil Mil aims to empower DIL-MIL dyads with knowledge, skills, and social support critical to the mitigation of GBV and related adverse health outcomes among DILs. We chose antenatal care as the context for implementing this intervention because of women's nearly universal use of antenatal care in urban India. A phase 1 pilot study demonstrated that our approach is acceptable and likely to be safe. The aim of this R21 is to conduct a phase 2 trial to examine the feasibility, safety, and potential effectiveness of Dil Mil in order to determine if a phase 3 effectiveness trial is merited. The proposed study is a randomized controlled trial with 140 dyads comprising pregnant DILs (aged 18 to 30 years, in their first or second trimester of pregnancy, with a history of GBV) and their MILs. Recruitment will take place at four primary health centers serving poor communities in Bangalore. Dyads will be offered standard care or standard care plus the Dil Mil intervention, and evaluations will be conducted at 3 months and 6 months postpartum. We will characterize the study population using descriptive statistics and assess feasibility and safety of the intervention using qualitative and quantitative data (Aim 1). Data on the effect of the intervention on intermediary outcomes-the empowerment of DILs and MILs (Aim 2)-and on the incidence of GBV among DILs during the first 6 months postpartum, DILs'perceived quality of life and psychosocial status, and maternal and infant health outcomes (Aim 3) will be analyzed using the intention-to-treat principle. Based on this evidence, we will determine if a phase 3 trial is merited. In conclusion, this study will generate important insights on a novel, urgently needed response to GBV in a high prevalence setting and is highly likely to have a significant public health impact. PUBLIC HEALTH RELEVANCE: A growing body of research indicates that gender-based violence (GBV) is a major global public health challenge. Yet, there is a dearth of evidence to guide program planning and policy-making efforts to reduce GBV. Our study will evaluate the feasibility, safety, and potential effectiveness of an innovative women's empowerment intervention to reduce GBV and related adverse health outcomes. It is expected that the study findings will provide evidence to determine if a phase 3 effectiveness trial is merited and advance the science underlying GBV prevention.